Tinder. I highly recommend Tinder. (Just go into every date with the goal of practicing going on a date.) And Meetup.com just to get out.

I don't think you'll have trouble. Your situation isn't strange. "I've had one long term relationship. It was with my ex-wife. I'm recently divorced," is not a strange thing to say on a date. It's a totally normal thing to say, and if you're a woman (which I am) you're used to hearing this. Also, it sounds like you like your wife, apart from the fact that you aren't having sex. That's also a tick in your favor if you start dating. Women (who aren't crazy) love it when men like their ex wives. Because it's nice.

The fact that you have limited sexual experience, because your wife didn't want to try specific things, won't come up unless you're going to go to bed with someone. And at that point, it really won't matter to someone who finds you attractive. At all. I know for a fact that there are plenty of women in their 30s who would love the chance to expand the sexual horizon of an age appropriate partner, whose experience was previously limited by circumstance.